Fig. 4. High pressure phases of group 15 elements. Data were taken from literature ref. 7 and references therein, except for the A17, A7 and p-sc structures of P.9 The dotted line in P indicates the A7 to sc transition pressure previously reported in literature. The observation of the p-sc structure up to at least 30 GPa extends the existence of a rhombohedral unit cell (R3[combining macron]m) above the pressure limit where the same cell is reported in As. For all the elements the high pressure limit of the bcc structures (Im3[combining macron]m) represents the highest experimental pressure at which this structure has been observed.
